Methods, systems, and articles of manufacture for fingerprinting signatures and enhanced signature capturing for charge card transactions on mobile communication devices

ABSTRACT

A method and a system for fingerprinting signatures and enhanced signature capturing for charge card transactions on mobile communication devices identify and transform a signature into a normalized representation such as a bytestream including coordinate data and combine the normalized representation with some transaction information into combined data. The combined data is further transformed into fixed length data stored for further analyses or uses. Upon the receipt of a dispute, the stored representation(s) of the signature and some of the stored transaction information of the transaction in dispute may be transformed into a first fixed length data. The first fixed length data may be further compared with the stored fixed length data obtained at the time of the transaction to resolve the dispute. The representations of signatures of multiple transactions may be used to determine whether these multiple transactions belong to the same category or to different categories.

BACKGROUND

Charge cards such as credit cards, debit cards, etc. have beenextensively used in various type online or arm-length transactions forexchanges of proceeds with various products or services. Many users ormerchants, including those in brick and mortar stores as well as thoseon the go, use mobile communication devices (e.g., cell phones, tablets,laptops, etc.) paired with mobile point-of-sale terminals (e.g., creditcard terminals) to conduct transactions. These charge card transactionscollect signature information of the cardholders at the point-of-sale(POS) as a proof and authorization of transaction on the part of thecard holder and as a part of transaction records for future disputeresolution purposes. Modern point-of-sale terminals (e.g., credit cardreaders on or as a part of a mobile communication device) may includetouch-sensitive screen to capture cardholders' signatures entered by,for example, fingers or a writing utensil (e.g., a stylus). The mobilecommunication device or the point-of-sale terminal (collectively chargecard transaction device hereinafter) may then package a capturedsignature as an image file and store or transmit for storage purposesthe image file as a part of the transaction records.

To expedite the charge card payment process to increase the businessflow, these charge card transaction devices oftentimes compress theimage of a signature with some lossy image compression schemes to reducethe required time for transmitting the signature because the sizes oflossless images may take longer time for transmission and hence hinderthe business flow. For example, an image of a signature may be packagedin a TIFF (Tagged Image File Format) container including a compressedimage (e.g., a JPEG or Joint Photographic Experts Group image) to reducethe required time to transmit the captured signature image. Suchconventional approaches for capturing signatures may nevertheless besubjected to various payment card fraudulent schemes such as forgingsignatures, duplication or skimming of charge card information,signature forgery, after-the-fact fabrication of signatures (e.g.,fabrication of signatures after the transactions are completed), etc.

Therefore, there exists a need for an improved methods and systems forfingerprinting signatures and enhanced signature capturing for chargecard transactions on mobile communication devices.

SUMMARY

Disclosed are various embodiments relating to methods, systems, andarticles of manufacture for fingerprinting signatures and enhancingsignature capturing for charge card transactions on mobile communicationdevices. The method may identify a charge card transaction andtransaction information at a mobile communication device. Thetransaction information includes at least a signature of arepresentation of a signature of the cardholder of the charge card usedto pay for the transaction. The method may further capture one or morerepresentations for the signature and transform the one or moretransformations as well as at least some of the transaction into a dataentry by using a transform. In some embodiments, the one or morerepresentations captured for the signature comprise a bytestream ofcoordinate data along one or more strokes of the signature. The methodmay further identify the strokes of the signature and the correspondingcoordinates of the beginning point of each stroke.

One or more waypoints and their corresponding location data (e.g.,coordinates) along each stroke may also be identified in someembodiments. In these embodiments, the method may identify the waypointdata by using a constant or variable temporal interval or a constant orvariable spatial interval. In some of these embodiments where a constantor variable temporal interval is used, the mobile communication deviceidentifying or determining a waypoint may further identify a temporalinterval, a beginning time point for a beginning point of a stroke ofthe signature, and identify a waypoint along a stroke of the signatureafter the temporal interval from the beginning time point. In some ofthese embodiments where a constant or variable spatial interval is used,the mobile communication device identifying or determining a waypointmay further identify a curvature or linearity of a stroke and identify awaypoint along a stroke of the signature based at least in part upon theidentified curvature, the linearity, or a change in the curvature orlinearity of the stroke.

In some embodiments, the method may further normalize the signatureentered on an electronic visual display or a representation thereofcaptured by the mobile communication device. In these embodiments, themethod may assign a coordinate system that includes an origin for thesignature and assign a unit of measurement to at least the horizontalaxis or the vertical axis. In addition or in the alternative, the methodmay further determine a bounding box for the signature or for asignature field in an electronic visual display of the mobilecommunication device and determine a scaling factor for the bounding boxby using the bounding box and a predetermined size or a predetermineddimension. The method may then normalize the signature or arepresentation thereof by applying the scaling factor to the one or morerepresentations of the signature. In some embodiments, the method mayinput the one or more identified representations of the signature and atleast some of the transaction information into a hash function andgenerate a fixed length data entry as the data entry.

Some embodiments are directed at a method for using stored transactioninformation, one or more representations of a signature of a cardholder,and the data entry that is determined by transforming the one or morerepresentations and at least some of the transaction information. Inthese embodiments, the method may transmit the one or morerepresentations of a signature, the at least some of the transactioninformation, and the data entry to a remote computing system. The remotecomputing system may then store the one or more representations of thesignature, the at least some of the transaction information, and thedata entry in a data structure in a non-transitory machine readablemedium for the corresponding charge card transaction.

In some of these embodiments, the method may identify a request fordispute resolution for the charge card transaction filed by a buyer,identify the one or more representations of the signature and the atleast some of the transaction information for the charge cardtransaction stored in data structure in the non-transitory machinereadable medium, and identify the data entry stored in thenon-transitory machine readable medium for the charge card transaction.The method may further generating a first data entry by transforming theone or more representations of the signature and the at least some ofthe transaction information by using the transform, compare the firstdata entry with the data entry stored in the non-transitory machinereadable medium, and respond to or resolve the request for disputeresolution based at least in part upon comparison results. In theseembodiments, the transform is also used to transform the one or morerepresentations and at least some of the transaction information intothe data entry.

Some embodiments are directed at classifying multiple transactions byusing the stored representations of signatures for these multipletransactions. In these embodiments, the method may transmit the one ormore representations of the signature, the at least some of thetransaction information, and the data entry to a remote computing systemand determine whether a first charge card transaction and the chargecard transaction are to be classified into a same category or adifferent category. In some of these embodiments, the method thatdetermines whether a first charge card transaction and the charge cardtransaction are to be classified into a same category or a differentcategory may further identify one or more first representations of afirst signature for the first charge card transaction, examine the oneor more first representations of the first signature and the one or morerepresentations of the signature, and determine whether the one or morefirst representations of the first signature exactly or approximatelymatch the one or more representations of the signature.

In addition or in the alternative, the method may identify one or morefirst representations of a first signature for the first charge cardtransaction, optionally reconstruct the first signature by using atleast the one or more first representations of the first signature forthe first charge card transaction, optionally reconstruct the signatureby using at least the one or more representations of the signature forthe charge card transaction, examine the first signature and thesignature, and determine whether the first signature exactly orapproximately matches the signature. Moreover, the method may identifyone or more first representations of a first signature for the firstcharge card transaction, identify or determine a first expression forthe one or more first representations of the first signature for thefirst charge card transaction, identify or determine an expression forthe one or more representations of the signature for the charge cardtransaction, and determine whether the first expression exactly orapproximately matches the expression in some embodiments. In theseembodiments, the first expression includes a first mathematicalexpression, and the expression includes a mathematical expression.

Some embodiments are directed at an apparatus for implementing variousprocesses described herein. More details about the apparatus forimplementing various processes will be described in some of thesubsequent paragraphs with reference to one or more drawing figures.

Some embodiments are directed at an article of manufacture having storedthereupon a sequence of instructions which, when executed by a mobilecommunication device, causes the mobile communication device to performvarious processes or to invoke various modules described herein. Moredetails about the article of manufacture will be described in some ofthe subsequent paragraphs with reference to one or more drawing figures.

Further details of various embodiments of the invention are described inthe Detailed Description section with reference to respective figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the design and utility of various embodiments.It should be noted that the figures are not drawn to scale and thatelements of similar structures or functions are represented by likereference numerals throughout the figures. In order to better appreciatehow to obtain the above-recited and other advantages and objects ofvarious embodiments, a more detailed description of the inventionsbriefly described above will be rendered by reference to specificembodiments thereof, which are illustrated in the accompanying drawings.Understanding that these drawings depict only certain embodiments andare not therefore to be considered limiting of its scope, certainembodiments will be described and explained with additional specificityand detail through the use of the accompanying drawings in which:

FIG. 1 illustrates a high level flow diagram of a method or system forfingerprinting signatures and enhanced signature capturing for chargecard transactions on mobile communication devices in some embodiments.

FIG. 2 illustrates a high level flow diagram of a method or system forfingerprinting signatures and enhanced signature capturing for chargecard transactions on mobile communication devices in some embodiments.

FIG. 3 illustrates a more detailed flow diagram for a method or systemfor fingerprinting signatures and enhanced signature capturing forcharge card transactions on mobile communication devices in someembodiments.

FIGS. 4A-C illustrate a more detailed flow diagram of a method or systemfor fingerprinting signatures and enhanced signature capturing forcharge card transactions on mobile communication devices and the use ofcaptured signatures for further analyses in some embodiments.

FIG. 5 illustrates a flow diagram of a method or system forfingerprinting signatures and enhanced signature capturing for chargecard transactions on mobile communication devices and storing capturedsignatures on a remote computing system in some embodiments.

FIG. 6 illustrates a flow diagram for using captured signatures ofcharge card transactions for transaction dispute resolution in someembodiments.

FIG. 7 illustrates a flow diagram for identifying similar transactionsof a cardholder using captured signatures of charge card transactions insome embodiments.

FIG. 7A shows an illustrative signature in its entirety with an assignedcoordinate system having an origin and an optional bounding box for thesignature in some embodiments.

FIG. 7B illustrates two strokes of the signature shown in FIG. 7A.

FIG. 7C illustrates the beginning point and four waypoints for the firststroke illustrated in FIG. 7B.

FIG. 7D illustrates the beginning point and three waypoints for thesecond stroke illustrated in FIG. 7B.

FIG. 7E illustrates a simplified data structure including some entriesof information or data of transactions in some embodiments.

FIG. 7F illustrates a schematic flow diagram showing how embodiments maybe utilized as components of an integrated system;

FIG. 8 illustrates a flow diagram of an illustrative computing systemsuitable for implementing various embodiments described herein.

Various embodiments will now be described in detail with reference tothe drawings, which are provided as illustrative examples of theinvention so as to enable those skilled in the art to practice theinvention. Notably, the figures and the examples below are not meant tolimit the scope of embodiments. Where certain elements of embodimentscan be partially or fully implemented using known components (or methodsor processes), portions of such known components (or methods orprocesses) that are necessary for an understanding of the invention willbe described, and the detailed descriptions of other portions of suchknown components (or methods or processes) will be omitted for ease ofexplanation and to not obscure embodiments.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

Disclosed is a method, system, and computer program product forfingerprinting signatures and enhanced signature capturing for chargecard transactions on mobile communication devices in variousembodiments. The method or system may identify a signature entered into,for example, a touchscreen of a mobile communication device and thentransform the identified signature into a normalized representation. Thenormalized representation of the signature may comprise a bytestreamhaving coordinate data of various captured points in the signature. Themethod or system may then fingerprint the signature by combining thenormalized representation of the signature with some transactioninformation to form combined data. The combined data may be furthertransformed into a fixed length data entry that is stored for furtheranalyses or uses. For example, the method or system may apply a hashfunction to the combined data to generate a hash function output or ahash value for the combined data at or near the time of the charge cardtransaction.

The normalized representation and the transaction information used togenerate the fixed length data entry may be stored together with thefixed length data entry on the mobile communication device, on a remotecomputing system, or on both. Upon receipt of a dispute for atransaction, the method or system may retrieve the stored normalizedrepresentation of the signature and some of the stored transactioninformation of the transaction in dispute. The method or system mayperform an additional transform on the stored normalized representationof the signature and some of the stored transaction information togenerate another fixed length data. This another fixed length data entrymay then be compared with the stored fixed length data entry. If the twodata entries match, the method or system may then determine that therewas a signature captured at the time of the transaction, and the storeddata entry is the same as the new data entry generated from thetransaction information and the normalized representation of thesignature. In other words, the method or system may verify that therecords for the transaction in dispute are consistent and may respond tothe dispute accordingly.

Moreover, the representations of signatures of multiple transactions maybe also used to determine whether these multiple transactions belong tothe same category or to different categories. For example, the method orsystem may compare the normalized representation of a signature oranother expression therefor of a transaction in question with thecorresponding data of a known, valid transaction to determine whetherthe transaction in question also constitutes a known, valid transaction.Similarly, the method or system may compare the normalizedrepresentation of a signature or another expression therefor of atransaction in question with the corresponding data of a known,fraudulent transaction to determine whether the transaction in questionalso constitutes a known, fraudulent transaction.

FIG. 1 illustrates a high level flow diagram of a method or system forfingerprinting signatures and enhanced signature capturing for chargecard transactions on mobile communication devices in some embodiments. Amobile communication device includes a portable device having anelectronic visual display (e.g., a touchscreen) for displayinginformation and also for accepting signatures of cardholders of chargecards. A mobile communication device may also include the capability ofreading charge card information from charge card either as a nativefunctionality of the device itself or as an add-on function whenoperating in conjunction with another peripheral device communicativelycoupled to the mobile communication device.

In some embodiments, a mobile communication device comprises a mobilecomputer (e.g., a laptop computer), a mobile Internet device (MID), apersonal digital assistant (PDA), an enterprise digital assistant (EDA),a portable media player capable of telecommunication purposes (e.g., anmedia player with wireless communication capabilities), a portableentertainment device with telecommunication purposes (e.g., a portablegaming device with wireless communication capabilities), a mobile phone,a portable navigation device with telecommunication capabilities, acombination of any of the aforementioned devices, or any devices withtelecommunication capability as well as the aforementioned capability ofreading charge card information and accepting cardholders signatures.

In these embodiments illustrated in FIG. 1, a buyer 102 carrying acharge card 104 (e.g., a credit card) and a seller (e.g., a merchant ora store clerk) 106 may wish to enter a transaction where the buyer 102wishes to purchase some products or services from the seller 106 byusing the charge card 104. The seller 106 in this illustrated examplemay or may not necessarily have a brick-and-mortar store and may utilizea mobile payment 108 (e.g., a cellular phone, a tablet, etc.) tocomplete transactions with buyers. In these embodiments, the mobilecommunication device 108 is wirelessly connected to a backend server 114to enable transfer or exchange of information or data therebetweenthrough a network 114 (e.g., a cellular network or the Internet). Thebackend server may include therewithin or may be operatively andremotely coupled to some storage device 116 to read data or informationfrom or to write data or information to the storage device.

The mobile communication device 108 of the seller 106 may be operativelyconnected to the backend server 114 in such a way that the backendserver 114 may recognize that the connected mobile communication device108 is associated with a particular seller 106 and may further updateits database(s) on the coupled storage device 116 with data orinformation regarding various transactions involving the seller 106 orthe buyer 102. For example, the backend server 114 may update the useror the merchant account associated with a particular seller 106. Duringa transaction with the buyer 102, the seller 106 may use the mobilecommunication device 108 to process payment from the buyer 102 by, forexample, reading information from the charge card 104. The mobilecommunication device 108 may read the charge card information, identifyinformation about the item(s) involved in the transaction, capture thesignature of the buyer 102, and perform various functions as describedbelow with reference to FIGS. 2-7A-D. The mobile communication device108 may store various transaction information, one or morerepresentations of a signature, and a transformed data entry for the oneor more representations of the signature either in one or more datastructures of the mobile communication device 108, in one or more datastructures on or operatively coupled to the backend server 114, or inboth.

The mobile communication device 108 may identify information from thecharge card by, for example, swiping the magnetic strip (if any) on thecharge card, interacting with the chip embedded (if any) on the chargecard 104, scanning or photographing certain code(s) or portion(s) of thecharge card 104, etc. and subsequently transmit the identifiedinformation through the network 112 to various payment institutions 150including an acquiring bank or a card issuing bank 108, a paymentgateway 120, a payment processor 122 associated with the acquiring bank108, the card association 123 (e.g., VISA®, Master®, JCB®, Discover®,American Express®, etc.)

These payment institutions in turn authenticate the charge card, processthe payment information and request, and make settlement such that thetransaction is fulfilled between the seller 106 and the buyer 102. Itshall be noted that the backend server 114 may, either by itself or inconjunction with one or more other servers, either interface with thepayment institutions 150 or become a part of the payment institutions150 to facilitate the exchange or transmission of information or data tocomplete transactions. For example, the backend server 114 may assumethe role to become the roles of the payment gateway 120, the acquiringbank 108, or the payment processor 122 for the acquiring bank 108 insome embodiments.

FIG. 2 illustrates a high level flow diagram of a method or system forfingerprinting signatures and enhanced signature capturing for chargecard transactions on mobile communication devices in some embodiments.In these embodiments illustrated in FIG. 2, the method or system mayidentify a charge card transaction and information related to thetransaction and/or the charge card on a mobile communication device at202. For example, the mobile communication device may a built-in orexternally attached charge card reader to read the charge cardinformation for a transaction between a seller and a buyer. The relatedinformation may include, for example, transaction data and the signatureof the cardholder entered on an electronic visual display (e.g., atouchscreen of the mobile communication device). The transaction datamay include temporal information such as date and time about thetransaction, information (e.g., description, quantity per item, amountper item, etc.) about the product or service item(s) purchased in thetransaction, information about the seller, charge card information(e.g., masked charge card number), monetary information (e.g., thesub-total, sales tax, tip, etc.) of the transaction, transactionidentifier (e.g., an Electronic Data Capture or EDC transaction ID), orany other suitable information.

At 204, the method or system may capture one or more representations ofthe signature of the card holder to complete the transaction. Thecardholder may enter his or her signature on an electronic visualdisplay (e.g., a touchscreen) of the mobile communication device of theseller by hand or with a writing utensil (e.g., a stylus). The method orsystem may then capture one or more representations of the signature ina variety of different manners. In some, the method or system maycapture the signature in the form of one or more streams of digital datainstead of an image of the signature in conventional approaches. Astream of digital data may include a bytestream, a sequence of bytes, ora sequence of octets (hereinafter bytestream) converted or transformedfrom the signature. In some of these illustrated embodiments, the methodor system may capture the beginning point of the signature or thebeginning point of each stroke of the signature and receive the entiresignature entered on the electronic visual display by the cardholder.

In these embodiments, the method or system may then determine multiplewaypoints for the signature or for each stroke of the signature. Awaypoint may be determined by, for example, analyzing the curvature orrate of change of the signature or each stroke of the signature andcapturing a waypoint at the appropriate location to generate a segmentthat approximates a stroke or a part of a stroke of the signature. Forexample, the method or system may use one or more forms of a Beziercurve (e.g., linear, quadratic, cubic, or even higher-order Beziercurve) and capture waypoints at various locations around which curvaturechanges in the signature or stroke to closely approximate a signature ora stroke captured on an electronic visual display of a mobilecommunication device. In some other embodiments, the method or systemmay insert waypoints at fixed spatial intervals (e.g., one way pointsfor every fixed number of pixels).

In some other embodiments, the method or system may capture the one ormore representations of the signature in nearly real-time when thesignature is being entered. For example, upon the display of thesignature screen and before the completion of the signature (e.g.,receiving the click on an “Accept” button to indicate the cardholder'sacceptance of the signature), the method or system may record thebeginning point of each stroke of the signature while no input on theelectronic visual display indicates the end of a stroke or signature.The method or system may then capture the locations of the cardholder'sfinger or writing stylus at a fixed or variable temporal interval (e.g.,one captured location on screen every 20 milliseconds). Yet in someother embodiments, the method or system may use a combined technique tocapture one or more representations of the signature by using a constantor variable temporal interval capturing scheme and a constant orvariable spatial interval (e.g., distance between two neighboringwaypoints).

For the ease of description and explanation, the signature capturingscheme employing a constant or variable temporal interval may bereferred to as a temporal signature capture scheme, and the signaturecapturing scheme employing a constant or variable spatial interval maybe referred to as a spatial signature capture scheme. The waypoints orlocations may be captured in a form of the absolute coordinates withrespect to a universal origin (e.g., the lower left corner of thedisplay area or the signature field) or relative coordinates withrespect to a custom defined origin (e.g., a center of the waypoints orlocations in the electronic visual display of the mobile communicationdevice. In some embodiments, each stroke may be captured as a singlestream of digital data (e.g., a bytestream), and a signature may thusinclude a plurality of bytestreams that collectively represent thesignature. In some other embodiments, a signature including one or morestrokes may be captured as a single stream of digital data (e.g., asingle bytestream).

At 206, the method or the system may transform the one or morerepresentations and at least some of the transaction information into afixed length data at or near the time of the charge card transaction.Mobile communication devices may have different screen sizes andresolution, and different signatures may have different numbers ofstrokes. Therefore, the captured one or more representations may havedifferent “waypoints” regardless of whether a spatial signaturecapturing scheme or a temporal signature capturing scheme is used. Forexample, a tablet computer typically has a larger electronic display andthus may accommodate a larger signature field. Electronic display havinghigher display resolution may capture finer details of a signature andthus produce a larger amount of data when used to capture signatures.

More complex signatures may also produce larger amount of data. On theother hand, the same charge card may nevertheless be used on varioussuch mobile communication devices that produce the representations ofthe same cardholder's signature with different sizes or amount of data(e.g., different number of bytes in the captured bytestreams). Suchvariations in the representations of the signature may presentdifficulties in future analyses of the signatures or in storage. Forexample, the first bytestream of the signature captured on a firstmobile communication device may contain only 16 bytes of data, but thesecond bytestream of the same signature captured on a second mobilecommunication device may nevertheless contain 24 bytes of data.

The discrepancy between the two representations of the same signaturemay cause inefficiency in the storage solution by requiring a field ofat least 24 bytes to store 16 bytes of data. Therefore, the method orsystem may transform the captured one or more representations of asignature into a fixed length data by using a first transform. In someembodiments, the method or system may use a hash function to hash theone or more representations of a signature or the one or morerepresentations of a signature combined with other information (e.g.,some transaction information) into a hash value of a fixed length. Thetransform may include a non-colliding hash function or any other hashfunction that transforms the same input into the same hash value in someembodiments. The transform may have a nearly negligible probability(e.g., one in several billions) of transforming two different inputvalues into the same output.

The transform may be non-invertible for security purposes in someembodiments, and may be invertible in some other embodiments. In thelatter embodiments where the transform is invertible, the output of thetransform may be transformed back to the input by using, for example,the inverse transform. For example, the method or system may transformthe one or more representations of a signature into a first bytestreamby using a transform and use the inverse of the transform to transformthe first bytestream back into the original first bytestream. At 208,the method or system may transmit, for storage purposes, the one or morerepresentations of the signature, at least some of the transactioninformation, and the fixed length data in a non-transitory computeraccessible storage medium on a remote computing system (e.g., the remoteserver 114 of FIG. 1) in some embodiments. In some other embodiments,the one or more representations of the signature, at least some of thetransaction information, and the fixed length data may be stored in anon-transitory computer accessible storage medium on the mobilecommunication device. Yet in some other embodiments, the one or morerepresentations of the signature, at least some of the transactioninformation, and the fixed length data may be stored in both anon-transitory computer accessible storage medium on the mobilecommunication device and a non-transitory computer accessible storagemedium on a remote computing system.

FIG. 3 illustrates a more detailed flow diagram for a method or systemfor fingerprinting signatures and enhanced signature capturing forcharge card transactions on mobile communication devices in someembodiments. In these embodiments illustrated in FIG. 3, the method orsystem may first identify a charge card transaction and informationrelated to the transaction on a mobile communication device insubstantially similar manners as those described for 202 of FIG. 2. At304, the method or system may normalize the signature captured on asignature capturing device such as an electronic visual display of themobile communication device. As presented above in FIG. 2, mobilecommunication devices may have different screen sizes and resolutioncapabilities, and different signatures may have different numbers ofstrokes. Therefore, captured signatures may have different “waypoints”regardless of whether a spatial signature capturing scheme or a temporalsignature capturing scheme is used.

In normalizing captured signatures, the method or system may, forexample, assign a coordinate system including an origin for thesignature entered on the mobile communication device or for thesignature field before, during, or after the signature is entered. Themethod or system may choose an absolute coordinate system having auniversally existing origin (e.g., the lower left corner or the centerof the signature field or the electronic visual display). The method orsystem may use a pixel width as a unit of measure in both the horizontaland vertical direction or may use the same unit of measure acrossdifferent mobile communication devices (e.g., the lower left hand cornerof the signature field or electronic visual display being the origin (0,0), and the upper right hand corner of the signature field or electronicvisual display having the coordinates (4, 1) regardless of theresolution or size of the actual signature field or the electronicvisual display.

In some embodiments, the method or system may identify a bounding boxthat constitutes the smallest polygon containing the signature andnormalize the size of the bounding box by scaling the bounding box to abounding box having a predetermined, universal size (e.g., predeterminedwidth, predetermined length, or both) across different platforms. Themethod or system may then capture the coordinates of the beginning pointand waypoints of each stroke relative to the normalized bounding box insome embodiments. In some other embodiments, the method or system mayhave pre-captured one or more representations of the signature. In theseembodiments, the method or system may then transform the captured one ormore representations of the signature according to the normalization ofthe bounding box.

For example, the bounding box may be normalized by using a geometrictransform to a normalized bounding box having predetermineddimension(s). The method or system may then use the same geometrictransform to transform the captured one or more representations (e.g.,the coordinates of the beginning point(s) and/or the waypoint(s)). Insome embodiments where an image is captured for 304, the method orsystem may normalize the captured signature image by using similartechniques described above. For example, the method or system maydetermine the bounding box for the signature image and normalize thesignature by applying a geometric transform to the captured image suchthat the bounding box may be transformed to a universal bounding boxhaving predetermined dimension(s). In some other embodiments where thesignature has been captured as one or more representations such as oneor more streams of digital data (e.g., coordinates), the method orsystem may also apply substantially similar techniques as describedabove to normalize the captured one or more representations of thesignature.

At 306, the method or system may identify one or more strokes orsegments in the normalized signature. For example, the method or systemmay first identify the beginning of the signature capturing session asthe presentation of the signature screen to a cardholder and the end ofthe signature capturing session upon receiving a cardholder's input(e.g., clicking on “Accept” button). The method or system may identifythe beginning of a stroke when there is no input received from thecardholder on the electronic visual display (e.g., lifting the signingfinger or stylus). By identifying beginnings of strokes, the method orsystem may hence identify strokes for the signature. At 308, theidentified strokes or segments of the strokes may be transformed into orcaptured as one or more representations (e.g., one or more streams ofdata) by capturing, for example, the absolute or relative coordinates ofthe beginning points and waypoints as described above for FIG. 2.

The method or system may optionally combine the one or morerepresentations with at least some of the transaction information in avariety of different manners at 310. At 312, the method or system maythen transform the one or more representations of the signature or theone or more representations of the signature combined with at least someof the transaction information into a fixed length data entry insubstantially similar manners as those described for 206 of FIG. 6. At314, the method or system may store or transmit for storage purposes theone or more representations, the at least some of the transactioninformation, and the fixed length data entry in one or morenon-transitory computer accessible or machine accessible media on themobile communication device, a remote computing system, or both.

FIGS. 4A-C illustrate a more detailed flow diagram of a method or systemfor fingerprinting signatures and enhanced signature capturing forcharge card transactions on mobile communication devices and the use ofcaptured signatures for further analyses in some embodiments. In theseembodiments illustrated in FIGS. 4A-C, the method or system may identifytransaction information and a first signature related to a charge cardtransaction on a mobile communication device at 402 in substantiallysimilar manners as those described for 302 of FIG. 3 or 202 of FIG. 2.The first signature or one or more representations thereof may then benormalized at 404 by using substantially similar techniques describedabove with reference to FIG. 3 or FIG. 2 in some embodiments.

For example, the method or system may assign a coordinate system ordetermine a bounding box to normalize the captured signature or the oneor more representations of the signature (e.g., a computer image of thesignature or a bytestream of the signature). Normalization mayaccommodate variations in, for example, sizes or resolution ofelectronic visual display and/or complexities of signatures. In someembodiments where the final representation of the first signature isfurther transformed into a fixed length data entry (e.g., by using ahash function), the normalization at 404 may be optional because thetransformation may also accommodate such variations in, for example,sizes or resolution of electronic visual display and/or complexities ofsignatures. The method or system may identify the strokes or segments ofone or more strokes of the first signature at 406 by using substantiallysimilar techniques as those described for 306 of FIG. 3.

At 408, the captured first signature, the strokes or segments of strokesof the first signature, or a normalized representation thereof may betransformed into a first representation for the first signature. In someembodiments, the first representation for the first signature mayinclude a bytestream for the first signature or a bytestream for eachstroke of the first signature. The one or more bytestreams may includethe absolute or relative coordinates of the beginning points and variouswaypoints of the first signature or each stroke of the first signature.At 410, the first representation obtained at 408 may be furthertransformed into a first fixed length data entry by using a secondtransform in some embodiments. In some of these embodiments, the secondtransform may include a hash function.

For example, the second transform may include a non-colliding hashfunction or any other hash function that transforms the same input intothe same hash value in some embodiments. The second transform may have anearly negligible probability (e.g., one in several billions) oftransforming two different input values into the same output. The secondtransform may be non-invertible for security purposes in someembodiments, and may be non-invertible in some other embodiments. In thelatter embodiments where the second transform is invertible, the outputof the transform may be transformed back to the input by using, forexample, the inverse transform of the second transform. At 412, themethod or system may transmit, for storage purposes, the firstrepresentation of the first signature, at least some of the transactioninformation, and the first fixed length data in one or morenon-transitory computer accessible storage media on the mobilecommunication device, a remote computing system (e.g., the remote server114 of FIG. 1), or both in some embodiments.

FIG. 4B illustrates a flow diagram of a method or system for using thestored transaction information, representations of signatures, and thetransformed fixed length data entries of the representations or of therepresentations combined with at least some transaction information forresolving disputed transactions in some embodiments. In some of theseembodiments illustrated in FIG. 4B, the method or system may receive, at414 from a mobile communication device, the first representation of asignature for a transaction, at least some of the stored transactioninformation, and the corresponding fixed length data entry at a remotecomputing system such as a server 114 in FIG. 1. The method or systemmay store at 416 the first representation of a signature of a cardholderof a charge card for a transaction, at least some of the storedtransaction information, and the corresponding fixed length data entryin one or more data structures, one or more tables, one or more lists,one or more database tables, or any combinations thereof (collectively“data structure” hereinafter) on the remote computing system.

In some of these embodiments, the method or system may optionally formatat least some of the aforementioned information or data to be receivedfor storage purposes. The method or system may receive a request fordispute resolution from, for example, a cardholder for a secondtransaction that was paid for by the charge card at 418. For example,the cardholder may call or log an electronic request for disputeresolution for a second transaction that was purportedly paid for by thecharge card of the cardholder. The call or the electronic request may bearranged and forwarded to a computing system for further processing ofthe request for dispute resolution. At 420, the method or system mayidentify information that is related to the second transaction from thedata structure upon which information about the second transaction isstored. In some embodiments, the method may identify the one or moresecond representations of the signature for the second transaction, atleast some of the stored second transaction information for the secondtransaction at 422 from the information identified at 420 for furtherprocessing the request for dispute resolution.

At 424, the method may transform the stored one or more secondrepresentations of the second signature and the at least some of thesecond transaction information into the second fixed length data entryby using the same second transform that is used at 410. At 426, themethod or system may then compare the second fixed length data entrywith the fixed length data entry that was transformed at or shortlyafter the completion of the second transaction and was already stored inthe data structure. The method or system may then respond to the requestfor dispute resolution by using the comparison results at 428. Forexample, the method or system may compare the two fixed length dataentries at 426 and determine that the two fixed length data entriesmatch each other.

The method or system may thus determine that the stored at least sometransaction information and the stored second representations of thesignature have not been mutilated since the time of completion of thetransaction, and that the second transaction was a valid transactionwith the required signature. The method or system may thus generate aresponse indicating that the stored information related to the secondtransaction remains unmutilated, and that the second transaction wasauthorized as evidenced by the unaltered signature based at least inpart upon the comparison results. On the other hand, if the method orsystem, after comparison, finds that the re-determined fixed length dataentry does not match the already stored fixed length data entry of thesecond transaction, the method or system may then determine that thesecond transaction was not properly authorized and issue a chargeback tothe cardholder.

In some embodiments, the method or system may further compare, at 426,the signature, the one or more representations of the signature, or oneor more other representations of the signature of a transaction indispute with a known signature, known one or more representations of theknown signature, or known one or more other representations of the knowsignature to determine whether or not the transaction in dispute isproperly authorized by the cardholder of the charge card. For example,the method or system may determine whether the image of the signature ofthe transaction in dispute exactly or approximately matches a known,valid signature of the cardholder to determine whether the transactionin dispute was properly authorized by the cardholder. As anotherexample, the method or system may compare the bytestream of a known,valid signature of the cardholder with the corresponding bytestream ofthe transaction in dispute to determine whether or not the signature ofthe transaction in dispute exactly or approximately matches the known,valid signature of the cardholder.

In some of these embodiments, the method or system reconstruct thesignature of the transaction in dispute as well as the known, validsignature of the cardholder by using the stored coordinate informationin the respective bytestream and determine whether the two reconstructedsignatures are sufficiently close to each other (e.g., within a certainpredetermined range or percentage). For example, the method or systemmay retrieve the same set of points (e.g., beginning point(s) and/orwaypoint(s)) from both images and compute the distances (e.g., Euclideandistances) between these points in each set. If the computed distancesare identical or sufficiently close, the method or system may determinethat these two signatures are identical. As yet another example, themethod or system may represent each representation of signature as amathematical expression (e.g., a linear, quadratic, cubic orhigher-order Bezier curve, an n-th order polynomial, etc.)

The method or system may then mathematically determine whether these twomathematical expressions of the two signatures (the signature for thetransaction in dispute and the known, valid signature) are identical orsufficiently similar (e.g., same order of polynomials havingsufficiently similar coefficients or different orders of polynomialsrepresenting similar curves in space, etc.) It shall be noted that othermethods or techniques may also be used to determine whether the twosignatures or the two representations of the signatures are identical orsufficiently similar, and that the aforementioned techniques are notintended to and thus shall not be construed as limit the scope of otherembodiments or the scope of the claims, unless otherwise explicitlyrecited or claimed.

FIG. 4C illustrates a flow diagram of a method or system for classifyingtwo transactions in a single category in some embodiments. In someembodiments illustrated in FIG. 4C, the method or system may identify athird transaction at 430. The third transaction may include a known,valid transaction in some embodiments where the cardholder properlyauthorized the third transaction by placing a genuine signature of thecardholder to complete the third transaction. The third transaction maycomprise a known, fraudulent transaction in some other embodiments whereit has been determined that the signature associated with the thirdtransaction is known to be forged by a fraudster. At 432, the method orsystem may retrieve the one or more third representations and/or thestored third transaction information for the third transaction.

The method or system may optionally reconstruct the third signature byusing the stored one or more third representations and/or the storedthird transaction information at 434 in substantially similar manners asdescribed immediately above with reference to FIG. 4B. At 436, themethod or system may identify a fourth transaction of interest forclassification. The method or system may similarly retrieve the one ormore fourth representations for the fourth signature and/or the storedfourth transaction information for the fourth transaction at 438 andoptionally reconstruct the fourth signature at 440 by using the one ormore fourth representations and/or the stored fourth transactioninformation. The method or system may then compare the informationrelated to the fourth transaction with the corresponding informationrelated to the third transaction at 442.

The information related to a transaction may include, for example, theone or more representations of the signature for the transaction, thereconstructed signature (if available), the fixed length data entryobtained by transforming the one or more representations or bytransforming the one or more representations combined with at least someof the stored transaction information for the transaction in someembodiments. At 444, the method or system may then determine whether thefourth transaction is to be classified as to belong to the same category(e.g., known valid transaction or fraudulent transaction) based at leastin part upon the comparison results obtained at 442. For example, themethod or system may compare the fourth signature (or one or morerepresentations thereof) with the third signature (or one or more thirdrepresentations thereof) at 422 to determine whether the fourthsignature (or one or more representations thereof) exactly orapproximately matches the third signature (or one or more thirdrepresentations thereof). If the determination result is affirmative,the method or system may thus classify the fourth transaction into thesame class or category as the third transaction. Otherwise, the methodor system may classify the fourth transaction into a different class orcategory.

FIG. 5 illustrates a flow diagram of a method or system forfingerprinting signatures and enhanced signature capturing for chargecard transactions on mobile communication devices and storing capturedsignatures on a remote computing system in some embodiments. In theseembodiments illustrated in FIG. 5, the mobile communication device 502may receive or identify, for example, the cardholder signature andtransaction information about a transaction between the seller and thecardholder of a charge card used to pay for the transaction. Thedescribed method or system may capture or transform the signature orstrokes thereof into one or more normalized representations by using afirst transform at 504.

For example, the method or system may capture or transform thecardholder's signature into a normalized bytestream as previouslydescribed. At 506, the method or system may optionally combine thenormalized one or more representations of the cardholder's signaturewith at least some transaction information (e.g., transaction date,transaction time, transaction identification, etc.) to form combinedtransaction data. The method or system may then transform the combinedtransaction data into a fixed length data entry by using a secondtransform at 508. For example, the method or system may use a hashfunction to hash the combined transaction data into a fixed length dataentry at 508. At 510, the fixed length data entry and at least a part ofthe transaction information (e.g., combined transaction data) to aremote computing system 512 (e.g., the backend server 114 in FIG. 1).The remote computing system 512 may then store the transmitted fixedlength data entry and the at least a part of the transaction information(e.g., the combined transaction data obtained at 506) in one or moredata structures on the remote computing system at 514.

FIG. 6 illustrates a flow diagram for using captured signatures ofcharge card transactions for transaction dispute resolution in someembodiments. In these embodiments illustrated in FIG. 6, the method orsystem may first receive a request for dispute resolution at 604 from abuyer via various communication means 602 including telephonic devices,computing systems, or mobile communication devices, etc. A re-arranged(e.g., an rearrangement from a telephone call to an electronic form,etc.) request for dispute resolution 606 may be forwarded to a computingsystem 512 which may identify the stored fixed length data entry and/orat least a part of the stored transaction information (e.g., thecombined transaction data obtained at 506) related to the transaction indispute from a backend server at 608.

It shall be noted that the computing system may be the backend server insome embodiments. At 610, the method or system may transform theidentified at least a part of the transaction information into a firstfixed length data entry by using a second transform that was also usedto obtain the stored fixed length data entry. The method or system maythen determine whether the first fixed length data entry matches thestored fixed length data entry at 612 and, at 614, resolve thetransaction in dispute or respond to the request for dispute resolutionbased at least in part upon the determination results obtained at 612.More details about resolving request for dispute resolution aredescribed above with reference to FIG. 4B.

FIG. 7 illustrates a flow diagram for identifying similar transactionsof a cardholder using captured signatures of charge card transactions insome embodiments. In these embodiments illustrated in FIG. 7, acomputing system 702 may be operatively coupled to another computersystem 512 (e.g., the backend server 114 in FIG. 1) to perform varioustransaction classification or fraud investigation or detection tasks. At704, the method or system may identify at least some stored transactioninformation of a first transaction. In some embodiments, the firsttransaction includes a known, valid transaction paid for by a chargecard of a cardholder. In some other embodiments, the first transactionincludes a known, fraudulent transaction associated with an invalidsignature (e.g., a forged or invalid signature).

The method or system may identify a first normalized representation of afirst signature of the first transaction at 706. In some embodiments,the method or system may optionally reconstruct the first image of thefirst signature for the first transaction or determine a firstrepresentation of the first normalized representation at 708. Thereconstructed first image of the first signature may include a computerimage of the signature that is derived from the first normalizedrepresentation of the first signature. The first representation of thefirst normalized representation may include a mathematicalrepresentation or expression of the first normalized representation insome embodiments.

For example, the first representation may include a linear, quadratic,cubic or higher-order Bezier curve, an n-th order polynomial, etc. ofthe first normalized representation including absolute or relativecoordinates of various beginning points and waypoints of the firstsignature. At 710, the method or system may identify a secondtransaction of interest and the second normalized representation of thesecond signature associated with the second transaction of interest. Inthese embodiments, the method or system is to determine whether or notthe second transaction may be classified into the same class or categoryas the first transaction. At 712, the method or system may optionallyreconstruct the second image of the second signature for the secondtransaction or determine a second representation of the secondnormalized representation at 712.

The reconstructed second image of the second signature may include acomputer image of the second signature that is derived from the secondnormalized representation of the second signature. The secondrepresentation of the second normalized representation may include amathematical representation or expression of the second normalizedrepresentation in some embodiments. For example, the secondrepresentation may include a linear, quadratic, cubic or higher-orderBezier curve, an n-th order polynomial, etc. of the second normalizedrepresentation including absolute or relative coordinates of variousbeginning points and waypoints of the second signature.

At 714, the method or system may determine whether the first signatureexactly or approximately matches the second signature by examining thefirst image against the second image, by examining the firstrepresentation against the second representation, or by analyzing thefirst normalized representation against the second normalizedrepresentation in substantially similar manners as those described forFIGS. 4B-C above. In some embodiments where the determination result isaffirmative, the method or system may classify the first transaction andthe second transaction into the same class or category. Otherwise, themethod or system may classify the first transaction and the secondtransaction into different classes or categories.

FIG. 7A shows an illustrative signature in its entirety with an assignedcoordinate system having an origin 702A in some embodiments. FIG. 7Aalso illustrates the optional bounding box 704A for the signature. FIG.7B illustrates that the method or system may identify the two strokes ofthe signature, where 702B represents the first stroke, and 704Bindicates the second stroke in some embodiments. FIG. 7C illustrates thebeginning point of stroke (x11, y11−bs1) and the four waypoints for thefirst stroke. The four waypoints may be represented as (x12, y12−wp1),(x13, y13−wp2), (x14, y14−wp3), and (x15, y15−wp4). FIG. 7D illustratesthe beginning point of stroke (x21, y21−bs2) and the three waypoints forthe second stroke illustrated in FIG. 7B.

The three waypoints may be represented as (x22, y22−wp1), (x23,y23−wp2), and (x24, y24−wp3). Each X-coordinate of a point (e.g.,beginning point and/or waypoint) may be represented with a first fixedlength data. Similarly, each Y-coordinate of a point may also berepresented with a second fixed length data. It shall be noted thatX-coordinates and Y-coordinates need not be represented with the samelength of data. For example, the X-coordinate of a point may berepresented as four-bit, a one (1)-byte, two (2)-byte, or other lengthdata. Similarly, the Y-coordinate of a point may be represented asfour-bit, a one (1)-byte, two (2)-byte, or other length data.

FIG. 7E illustrates a simplified data structure including some entriesof information or data of transactions in some embodiments. Morespecifically, FIG. 7E illustrates a simplified data structure includingan illustrative normalized representation of a signature shown in FIGS.7A-D and other information or data of the pertinent transaction. Inthese illustrated embodiments, the method or system may store anormalized representation of the signature illustrated in FIGS. 7A-D inthe form of a bytestream representation in, for example, the firstcolumn of the illustrated data structure. The illustrative bytestreamrepresentation of the signature includes the coordinates of thebeginning point of the first stroke (e.g., x11, y11 or x21, y21),various waypoints along the strokes (e.g., x12, y12, x13, y13, x14, y14,x15, y15 or x21, y21, x22, y22, x23, y23, x24, y24).

Note that in this illustrated data structure, the method or system uses“0, 0” to indicate the end of a stroke in the signature. Theillustrative data structure may also include other information or dataabout the transaction such as date and time about the transaction,information (e.g., description, quantity per item, amount per item,etc.) about the product or service item(s) purchased in the transaction,information about the seller, charge card information (e.g., maskedcharge card number), monetary information (e.g., the sub-total, salestax, tip, etc.) of the transaction, transaction identifier (e.g., anElectronic Data Capture or EDC transaction ID), or any other suitableinformation.

FIG. 7F illustrates a schematic flow diagram of multiple systemsexecuting various functions in tandem described in this Application insome embodiments. In these embodiments illustrated in FIG. 7F, themobile communication device 730 may receive or identify, for example,the cardholder signature and transaction information about a transaction(TRX in FIG. 7F) between the seller and the cardholder of a charge cardused to pay for the transaction. The method or system may capture ortransform the signature or one or more strokes thereof into one or morenormalized representations (REP in FIG. 7F) by using a first transformat 732.

For example, the method or system may capture or transform thecardholder's signature into a normalized bytestream as previouslydescribed. At 736, the method or system may optionally combine thenormalized one or more representations of the cardholder's signaturewith at least some transaction information (e.g., transaction date,transaction time, transaction identification, etc.) to form combinedtransaction data. The method or system may then transform the combinedtransaction data into a fixed length data entry by using a secondtransform at 738. For example, the method or system may use a hashfunction to hash the combined transaction data into a fixed length dataentry at 738. The transaction information, the one or more normalizedrepresentations, the combined transaction data, the fixed length data,or any combination thereof may be stored on the mobile communicationdevice 730 and/or transmitted to a remote computing system 512 that isoperatively coupled to a storage device 740 for storage in one or moredata structures.

The method or system illustrated in FIG. 7F may further receive arequest for dispute resolution at 744 from a buyer via variouscommunication means 742 including telephonic devices, computing systems,or mobile communication devices, etc. The method or system may furtherforward a re-arranged (e.g., an rearrangement from a telephone call toan electronic form, etc.) request for dispute resolution to a computingsystem 748 which may be coupled to a storage device 750 and may furtheridentify the stored fixed length data entry and/or at least a part ofthe stored transaction information (e.g., the combined transaction dataobtained at 736) related to the transaction in dispute from a backendserver at 746.

It shall be noted that the computing system 748 and the computing system512 may be the same computing system or two or more separate computingsystems. Similarly, the storage device 740 and the storage device 750may be the same storage device or may be two different storage devices.At 752, the method or system may transform the identified at least apart of the transaction information into a first fixed length data entryby using a second transform that was also used to obtain the storedfixed length data entry. The method or system may then determine whetherthe first fixed length data entry matches the stored fixed length dataentry at 754 and, at 756, resolve the transaction in dispute or respondto the request for dispute resolution based at least in part upon thedetermination results obtained at 754.

The response or results of resolving the transaction in dispute may betransmitted to the complainant or the buyer directly from the computingsystem 748 or from the dispute resolution unit at 744 via communicationmeans 742. In some embodiments, the method or system may further utilizea computing system 758 to identify a first transaction and at least somestored transaction data thereof as well as one or more othertransactions at 760. In some embodiments, the first transaction includesa known, valid transaction paid for by a charge card of a cardholder. Insome other embodiments, the first transaction includes a known,fraudulent transaction associated with an invalid signature (e.g., aforged signature). The at least some stored transaction data mayinclude, for example, the normalized representations of the signaturesfor the first transaction and the one or more other transactions and /orany other pertinent data that may be related to these transactions andmay be used to classify or categorize the one or more other transactionsinto the same category or class as the first transaction.

The method or system may then examine the data of the signatures,information, and/or data of the transactions (e.g., the firsttransaction and the one or more other transactions) at 762 insubstantially similar manners as those described for FIG. 7 anddetermine whether the examined information or data of the one or moreother transactions exactly or approximately match the correspondinginformation or data of the first transaction at 764 in substantiallysimilar manners as those described for FIG. 7. In some embodiments wherethe examined information or data of the one or more other transactionsexactly or approximately match the corresponding information or data ofthe first transaction, the method or system may categorize or classifythe one or more other transactions into the same category or class asthe first transaction.

For example, if the first transaction constitutes a known, fraudulenttransaction, the method or system may also categorize or classify theseone or more other transactions as known, fraudulent transactions. Insome embodiments where the examined information or data of the one ormore other transactions do not exactly or approximately match thecorresponding information or data of the first transaction, the methodor system may categorize or classify the one or more other transactionsinto one or more different categories or classes from the firsttransaction.

FIG. 8 illustrates a block diagram of components of an illustrativecomputing system 800 suitable for implementing various embodiment of theinvention. For example, the exemplary computing system 800 may be usedto implement various processes as described in the preceding paragraphsand the figures such as various processes or modules of determiningwhether the first post is of interest, various analysis processes ormodules, various other determining processes or modules, variousprocesses or modules for performing various actions, etc. as describedin the remainder of the Application. Computer system 800 includes a bus806 or other communication mechanism for communicating information,which interconnects subsystems and devices, such as processor 807,system memory 808 (e.g., RAM), static storage device 909 (e.g., ROM),disk drive 810 (e.g., magnetic or optical), communication interface 814(e.g., modem or Ethernet card), display 811 (e.g., CRT or LCD), inputdevice 812 (e.g., keyboard), and cursor control (not shown).

According to one embodiment of the invention, computer system 800performs specific operations by one or more processors or processorcores 807 executing one or more sequences of one or more instructionscontained in system memory 808. Such instructions may be read intosystem memory 808 from another computer readable/usable storage medium,such as static storage device 809 or disk drive 810. In alternativeembodiments, hard-wired circuitry may be used in place of or incombination with software instructions to implement the invention. Thus,embodiments of the invention are not limited to any specific combinationof hardware circuitry and/or software. In one embodiment, the term“logic” shall mean any combination of software or hardware that is usedto implement all or part of the invention. In the single embodiment orin some embodiments, the one or more processors or processor cores 807may be used to perform various actions such as various actions,processes, or modules involving determining, analyzing, performingactions, etc. In some embodiments, at least one of the one or moreprocessors or processor cores 807 has the multithreading capability.

In one embodiment, the term “logic” shall mean any combination ofsoftware or hardware that is used to implement all or part of theinvention. In the single embodiment or in some embodiments, the one ormore processors or processor cores 807 may be used to perform variousacts such as various acts involving determining, analyzing, performingactions, etc. In some embodiments, at least one of the one or moreprocessors or processor cores 807 has the multithreading capability toexecute a plurality of threads to perform various tasks as described inthe preceding sections.

Various actions as described in the preceding paragraphs may beperformed by using one or more processors, one or more processor cores,or combination thereof 807. For example, various processes or modulesinvolving the determining action, various analysis processes or modules,etc. may be performed by one or more processors, one or more processorcores, or combination thereof.

The term “computer readable storage medium” or “computer usable storagemedium” as used herein refers to any non-transitory medium thatparticipates in providing instructions to processor 807 for execution.Such a medium may take many forms, including but not limited to,non-volatile media and volatile media. Non-volatile media includes, forexample, optical or magnetic disks, such as disk drive 810. Volatilemedia includes dynamic memory, such as system memory 808.

Common forms of computer readable storage media includes, for example,electromechanical disk drives (such as a floppy disk, a flexible disk,or a hard disk), a flash-based, RAM-based (such as SRAM, DRAM, SDRAM,DDR, MRAM, etc.), or any other solid-state drives (SSD), a magnetictape, any other magnetic or a magneto-optical medium, CD-ROM, any otheroptical medium, punch cards, paper tape, any other physical medium withpatterns of holes, RAM, PROM, EPROM, FLASH-EPROM, any other memory chipor cartridge, or any other medium from which a computer can read. Forexample, the various forms of computer readable storage media may beused by the methods or the systems to store either temporarily orpermanently information or data such as the one or more master regions,one or more master output layers, one or more global scratch layers,various transforms and inverse transforms, shapes, etc.

In an embodiment of the invention, execution of the sequences ofinstructions to practice the invention is performed by a single computersystem 900. According to other embodiments of the invention, two or morecomputer systems 800 coupled by communication link 815 (e.g., LAN, PTSN,or wireless network) may perform the sequence of instructions requiredto practice the invention in coordination with one another.

Computer system 800 may transmit and receive messages, data, andinstructions, including program, i.e., application code, throughcommunication link 815 and communication interface 814. Received programcode may be executed by processor 807 as it is received, and/or storedin disk drive 810, or other non-volatile storage for later execution. Inan embodiment, the computer system 800 operates in conjunction with adata storage system 831, e.g., a data storage system 831 that includes adatabase 832 that is readily accessible by the computer system 800. Thecomputer system 800 communicates with the data storage system 831through a data interface 833. A data interface 933, which is coupled tothe bus 806, transmits and receives electrical, electromagnetic oroptical signals that include data streams representing various types ofsignal information, e.g., instructions, messages and data. Inembodiments of the invention, the functions of the data interface 833may be performed by the communication interface 814.

In the foregoing specification, embodiments have been described withreference to the figures. It will, however, be evident that variousmodifications and changes may be made thereto without departing from thebroader spirit and scope of the invention, and that figures and examplesprovided are not provided to limit the scope of embodiments. Thus, thespecification and drawings are, accordingly, to be regarded in anillustrative rather than restrictive sense.

Further, where methods or processes described above indicate certainevents occurring in certain order, those of ordinary skill in the arthaving the benefit of this disclosure would recognize that the orderingmay be modified and that such modifications are in accordance with thevariations of the invention. Additionally, parts of methods may beperformed concurrently in a parallel process when possible, as well asperformed sequentially. It shall also be noted that although variousexamples described or drawings illustrated herein refer to a merchant'spairing a mobile communication device (e.g., a cellular phone) with awireless peripheral (e.g., a wireless transaction card reader), variousaspects described apply with full and equal effects to any users who arepairing their mobile communication devices to various types of wirelessperipherals. Therefore, the reference to a merchant or a wirelesstransaction card reader are not intended to and shall not be interpretedas limiting the scope of the application or the scope of the claims,unless otherwise specifically recited or claimed.

Accordingly, embodiments are intended to exemplify alternatives,modifications, and equivalents that may fall within the scope of theclaims.

What is claimed is:
 1. A machine implemented method for capturing andprocessing electronic signatures for a card transaction executed using amobile communication device, the method being performed by at least themobile communication device and comprising: the mobile communicationdevice identifying, at a touch screen and a charge card reader includedin or operatively coupled to the mobile communication device, a chargecard transaction and transaction information, the transactioninformation comprising product or service information related to atransaction between a user and an entity and a signature of the user ofthe charge card; the mobile communication device executing a firsttransformation of the signature into one or more representations of thesignature; the mobile communication device reducing computationalcomplexities of analyzing the signature at least by executing at leastone second transformation of a combination of the one or morerepresentations and at least some of the transaction information into afingerprint having a fixed length; and transmitting the one or morerepresentations and the at least some of the transaction informationfrom the mobile communication device to a remote server for storage in arepository via a computer network.
 2. The machine implemented method ofclaim 1, further comprising performing, at a remote server, one or moreoperations on the fingerprint and one or more other fingerprint havingthe fixed length or on the transaction, wherein the one or morerepresentations of the signature comprise a bytestream of coordinatedata along one or more strokes of the signature, and the one or moreoperations comprising at least one classification operation, frauddetection operation, or dispute resolution operation, or one or morecombinations thereof.
 3. The machine implemented method of claim 1,further comprising the mobile communication device: identifying a firststroke of the signature; identifying or determining beginningcoordinates of a beginning point of the first stroke; identifying ordetermining a first waypoint of the first stroke; and identifying ordetermining first waypoint coordinates of the first waypoint.
 4. Themachine implemented method of claim 1, further comprising the mobilecommunication device: segmenting the signature into a plurality ofstrokes including a first stroke; and identifying or determiningcoordinates of a start point of the first stroke and coordinates of afirst waypoint of the first stroke.
 5. The machine implemented method ofclaim 3, the mobile communication device identifying or determining thefirst waypoint further comprising the mobile communication device:identifying or determining a first temporal interval; identifying ordetermining a beginning time point for the beginning point; andidentifying or determining the first waypoint along the first strokeafter the first temporal interval from the beginning time point.
 6. Themachine implemented method of claim 3, the mobile communication deviceidentifying or determining the first waypoint further comprising themobile communication device: examining a curvature or linearity of thefirst stroke; and identifying or determining the first waypoint alongthe first stroke based at least in part upon the curvature, thelinearity, or a change in the curvature or linearity of the firststroke.
 7. The machine implemented method of claim 1, further comprisingthe mobile communication device normalizing the signature that isentered on an electronic visual display of the mobile communicationdevice.
 8. The machine implemented method of claim 7, the mobilecommunication device normalizing the signature further comprising themobile communication device: assigning a coordinate system including anorigin for the signature; and assigning a unit of measurement to atleast one of a horizontal axis and a vertical axis for the signature. 9.The machine implemented method of claim 7, the mobile communicationdevice normalizing the signature further comprising the mobilecommunication device: determining a bounding box for the signature orfor a signature field; determining a scaling factor by using thebounding box and a predetermined size or dimension for the bounding box;and normalizing the signature by applying the scaling factor to the oneor more representations of the signature.
 10. The machine implementedmethod of claim 1, further comprising the mobile communication device:executing a hash function with inputs comprising the one or morerepresentations of the signature and at least some of the transactioninformation; and generating a fixed length fingerprint of the signaturefor the fingerprint of the signature, wherein the first transformationcomprises a temporal signature acquisition process that converts thesignature received at the touch screen into at least one of the one ormore representations based on a temporal sequence.
 11. The machineimplemented method of claim 1, further comprising the mobilecommunication device transmitting the one or more representations of thesignature, the at least some of the transaction information, and thefingerprint of the signature to a remote computing system, the remotecomputing system storing the one or more representations of thesignature, the at least some of the transaction information, and thefingerprint of the signature in a non-transitory machine readable mediumfor the charge card transaction.
 12. The machine implemented method ofclaim 11, further comprising the remote computing system: receiving arequest for dispute resolution for the charge card transaction;retrieving the one or more representations of the signature and the atleast some of the transaction information for the charge cardtransaction stored in the non-transitory machine readable medium; andretrieving the fingerprint of the signature stored in the non-transitorymachine readable medium for the charge card transaction.
 13. The machineimplemented method of claim 12, further comprising the remote computingsystem: generating a first fingerprint of the signature by transformingthe one or more representations of the signature and the at least someof the transaction information by using the at least one secondtransformation, wherein the at least one second transformation-is alsoused to transform the one or more representations and at least some ofthe transaction information into the fingerprint of the signature;comparing the first fingerprint of the signature with the fingerprint ofthe signature stored in the non-transitory machine readable medium; andresponding to or resolving the request for dispute resolution based atleast in part upon comparison results.
 14. The machine implementedmethod of claim 1, further comprising the mobile communication devicetransmitting the one or more representations of the signature, the atleast some of the transaction information, and the fingerprint of thesignature to a remote computing system; and the remote computing systemdetermining whether a first charge card transaction and the charge cardtransaction are to be classified into a same category or a differentcategory.
 15. The machine implemented method of claim 14, the remotecomputing system determining whether a first charge card transaction andthe charge card transaction are to be classified into a same category ora different category further comprising the remote computing system:identifying one or more first representations of a first signature forthe first charge card transaction; examining the one or more firstrepresentations of the first signature and the one or morerepresentations of the signature; and determining whether the one ormore first representations of the first signature exactly orapproximately match the one or more representations of the signature.16. The machine implemented method of claim 14, the remote computingsystem determining whether a first charge card transaction and thecharge card transaction are to be classified into a same category or adifferent category further comprising the remote computing system:identifying one or more first representations of a first signature forthe first charge card transaction; reconstructing the first signature byusing at least the one or more first representations of the firstsignature for the first charge card transaction; reconstructing thesignature by using at least the one or more representations of thesignature for the charge card transaction; examining the first signatureand the signature; and determining whether the first signature exactlyor approximately matches the signature.
 17. The machine implementedmethod of claim 14, the remote computing system determining whether afirst charge card transaction and the charge card transaction are to beclassified into a same category or a different category furthercomprising the remote computing system identifying one or more firstrepresentations of a first signature for the first charge cardtransaction; identifying or determining a first expression for the oneor more first representations of the first signature for the firstcharge card transaction; identifying or determining an expression forthe one or more representations of the signature for the charge cardtransaction, wherein the first expression includes a first mathematicalexpression, and the expression includes a second mathematicalexpression; and determining whether the first expression exactly orapproximately matches the expression.
 18. A system for capturing andprocessing electronic signatures for a card transaction, the systemcomprising: a mobile communication device comprising a processor andconfigured or operable to execute a sequence of instructions toidentify, at a touch screen and a charge card reader included in oroperatively coupled to the mobile communication device, a charge cardtransaction and transaction information, the transaction informationcomprising product or service information related to a transactionbetween a user and an entity and a signature of the user of the chargecard; execute a first transformation of the signature into one or morerepresentations of the signature; reduce computational complexities ofanalyzing the signature at least by executing a second transformation ofa combination of the one or more representations and at least some ofthe transaction information into a fingerprint having a fixed length;and transmit the one or more representations and the at least some ofthe transaction information from the mobile communication device to aremote server for storage in a repository via a computer network. 19.The system of claim 18, the one or more representations captured for thesignature comprising a bytestream of coordinate data along one or morestrokes of the signature.
 20. The system of claim 18, the mobilecommunication device being further configured or operable to: identifyor determine a first stroke of the signature; identify or determinebeginning coordinates of a beginning point of the first stroke; identifyor determine a first waypoint for the first stroke; and identify firstwaypoint coordinates for the first waypoint.
 21. The system of claim 18,the mobile communication device being further configured or operable to:execute a hash function with one or more inputs comprising the one ormore representations of the signature and at least some of thetransaction information; and generate a fixed length fingerprint of thesignature for the fingerprint of the signature, wherein the firsttransformation comprises a temporal signature acquisition process thatconverts the signature received at the touch screen into at least one ofthe one or more representations based on a temporal sequence.
 22. Thesystem of claim 18, the mobile communication device being furtherconfigured or operable to transmit the one or more representations ofthe signature, the at least some of the transaction information, and thefingerprint of the signature to a remote computing system; determinewhether a first charge card transaction and the charge card transactionare to be classified into a same category or a different category;identify one or more first representations of a first signature for thefirst charge card transaction; examine the one or more firstrepresentations of the first signature and the one or morerepresentations of the signature; and determine whether the one or morefirst representations of the first signature exactly or approximatelymatch the one or more representations of the signature.
 23. A computerprogram product comprising a non-transitory machine readable storagemedium having stored thereupon a sequence of instructions which, whenexecuted by a mobile communication device, causes the mobilecommunication device to perform a process for capturing and processingelectronic signatures for a card transaction the process being performedby at least the mobile communication device and comprising: identifying,at a touch screen and a charge card reader included in or operativelycoupled to a mobile communication device, a charge card transaction andtransaction information, the transaction information comprising productor service information related to a transaction between a user and anentity and a signature of the user of the charge card; executing a firsttransformation of the signature into one or more representations for thesignature; and reducing computational complexities of analyzing thesignature at least by executing a second transformation of a combinationof the one or more representations and at least some of the transactioninformation into a fingerprint having a fixed length; and transmittingthe one or more representations and the at least some of the transactioninformation from the mobile communication device to a remote server forstorage in a repository via a computer network.
 24. The computer programproduct of claim 23, wherein the one or more representations capturedfor the signature comprise a bytestream of coordinate data along one ormore strokes of the signature.
 25. The computer program product of claim23, the process further comprising: identifying or determining a firststroke of the signature; identifying or determining beginningcoordinates of a beginning point of the first stroke; identifying ordetermining a first waypoint for the first stroke; and identifying ordetermining first waypoint coordinates for the first waypoint.
 26. Thecomputer program product of claim 23, the process further comprising:executing a hash function with one or more inputs comprising the one ormore representations of the signature and at least some of thetransaction information; generating a fixed length fingerprint of thesignature for the fingerprint of the signature, wherein the firsttransformation comprises a temporal signature acquisition process thatconverts the signature received at the touch screen into at least one ofthe one or more representations based on a temporal sequence.
 27. Thecomputer program product of claim 23, the non-transitory machinereadable storage medium having further stored thereupon a first sequenceof instructions which, when executed by a remote computing system,causes the remote computing system to perform a first process, the firstprocess comprising: receiving the one or more representations of thesignature at a remote computing system, the at least some of thetransaction information, and the fingerprint of the signature to aremote computing system; the remote computing system storing the one ormore representations of the signature, the at least some of thetransaction information, and the fingerprint of the signature in anon-transitory machine readable medium for the charge card transaction;the remote computing system identifying a request for dispute resolutionfor the charge card transaction; the remote computing system retrievingthe one or more representations of the signature and the at least someof the transaction information for the charge card transaction stored inthe non-transitory machine readable medium; the remote computing systemretrieving the fingerprint of the signature stored in the non-transitorymachine readable medium for the charge card transaction; the remotecomputing system generating a first fingerprint of the signature bytransforming the one or more representations of the signature and the atleast some of the transaction information by using the at least onesecond transformation, wherein the at least one second transformation isalso used to transform the one or more representations and at least someof the transaction information into the fingerprint of the signature;the remote computing system comparing the first fingerprint of thesignature with the fingerprint of the signature stored in thenon-transitory machine readable medium; and the remote computing systemresponding to or resolving the request for dispute resolution based atleast in part upon comparison results.